Method And System For Completing A Voice Call In A Cloud-Based Communication System Using A RAN Adapter

ABSTRACT

A method and system for completing a call between a first mobile device located at a first communication system and a second mobile device located at a second communication system is provided. A call initiation request including a request to complete a call with the second mobile device is received at a Radio Access Network (RAN) Adaptor (RA) from the first mobile device. The RA determines RAN-specific access parameters for the first mobile device and the second mobile device. The RA sends a call processing call initiation request including the RAN-specific access parameters and call initiation information for the first mobile device and the second mobile device to a cloud-based group call service. The RA establishes resources specific to the RAN in the RA. The resources include first resources at the first communication system and second resources at the second communication system. The call between the first mobile device and the second mobile device is completed using the first resources and the second resources.

BACKGROUND OF THE INVENTION

Communication systems, such as Land Mobile Radio (LMR) or Long-Term Evolution (LTE) cellular systems, are becoming more and more ubiquitous. Typically each of these communication systems includes a completely operational communication system. This requires significant financial outlays as well as substantial complexity when inter-system calls are placed.

In addition, updates to subscriber and talkgroup information needs to be coordinated across communication systems. Latency delays between communication systems can lead to problems connecting mobile devices and can also lead to missed calls or non-optimal use of resources.

Therefore a need exists for a method and system for completing voice calls between communication systems that resolve the problems of current communication systems.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, which together with the detailed description below are incorporated in and form part of the specification and serve to further illustrate various embodiments of concepts that include the claimed invention, and to explain various principles and advantages of those embodiments.

FIG. 1 depicts a system diagram of a communication system in accordance with an exemplary embodiment of the present invention.

FIG. 2 depicts a multi-tenant call processing services function in accordance with an exemplary embodiment of the present invention.

FIG. 3 depicts a schematic diagram of an LMR System RAN Adapter in accordance with an exemplary embodiment of the present invention.

FIG. 4 depicts a call flow diagram in accordance with an exemplary embodiment of the present invention.

Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.

The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 depicts a system diagram of a communication system 100 in accordance with an exemplary embodiment of the present invention. Communication system 100 comprises Call Processing System 101, Land Mobile Radio (LMR) System RAN 112, LMR System RAN 113, LMR System RAN 114, and Long Term Evolution (LTE) System RAN 115. Although only four Radio Frequency (RF) systems (112-115) are shown in FIG. 1 for clarity, it should be understood that communication system 100 could include additional or fewer RF systems. In addition, the type of RF systems within communication system 100 can vary, and can include all RF systems of a single type or any combination of compatible RF systems. Depending on the standard, mobile phones and other wireless connected devices are varyingly known as user equipment (UE), terminal equipment, mobile stations (MS), mobile units, mobile devices, and by other similar names.

A RAN is part of a mobile telecommunication system that implements a radio access technology. In exemplary systems, a RAN resides between a device, such as a mobile phone, a computer, or any remotely controlled machine, and provides connection with a core network, such as Call Processing System 101.

Call Processing System 101 preferably includes LMR System 1 RAN Adapters 102, LMR System 2 RAN Adapters 103, LMR System 3 RAN Adapters 104, Broadband System RAN Adapters 105, Multi-Tenant Call Processing Services 121, Multi-Tenant Call State Database 122, Multi-Tenant Mobility Services 131, and Multi-Tenant Mobility Database 132. In this exemplary embodiment, LMR System 1 RA 102 is operably coupled with LMR System 1 RAN 112 via link 132, LMR System 2 RA 103 is operably coupled with \LMR System 2 RAN 113 via link 133, LMR System 3 RA 104 is operably coupled with LMR System 3 RAN 114 via link 134, and Broadband System RA 105 is operably coupled with LTE RAN 115 via link 135. In an alternate exemplary embodiment, LMR System 1 RA 102 resides in LMR System 1 RAN 112, LMR System 2 RA 103 resides in LMR System 2 RAN 113, LMR System 3 RA 104 resides in LMR System 3 RAN 114, and Broadband System RA 105 resides in LTE RAN 115.

In accordance with an exemplary embodiment, Call Processing System 101 provides cloud-based call processing for multi-system, multi-tenant, multi-technology calls. Call Processing System 101 also preferably provides a fallback solution should a RAN either not desire or not be able to complete calls using Call Processing System 101. In this scenario, a RAN, such as LMR System 1 RAN 112, includes call processing and resource management functionality so that calls can be processed in standalone, fallback mode. The fallback solution provides a flexible system that can result in a single system, single tenant voice call processing service. In this exemplary embodiment, the fallback solution preferably provides a solution that results in a single system, single tenant access permission database that is kept up to date in real time from the multi-system, multi-tenant database, Multi-Tenant Mobility Database 132.

Call Processing System 101 includes a RAN Adaptation Layer, which is preferably comprised of a plurality of RAN Adapters, such as LMR System RAN Adapters 102, LMR System RAN Adapters 103, LMR System RAN Adapters 104, and Broadband System RAN Adapters 105. The RAN Adapters enable a common call processing solution yet still support different technologies, including LMR and Broadband technologies. In an exemplary embodiment, the RAN Adaptation Layer comprises one RAN Adapter per edge component (for example a RAN Adapter per RF or Console site), termination of the layer 2 message delivery protocol (for example a Transport Layer Security (TLS) link to the sites), conversion of technology specific messages to generic services messages, allocation of RAN specific resources (for example allocating RF channels for LMR sites or console bandwidth for console sites done on a per-RAN Adapter level), and RAN component functionality that is considered unique to the specific service rules associated with a RAN (for example resending call grants to an LMR site when a communication device registers at a site).

In accordance with FIG. 1, LMR System RAN Adapters 102 is coupled to LMR System RAN 112, LMR System RAN Adapters 103 is coupled to LMR System RAN 113, LMR System RAN Adapters 104 is coupled to LMR System RAN 114, and Broadband System RAN Adapters 105 is coupled to LTE System RAN 115.

Multi-Tenant Call Processing Services 121 provides multi-tenant, multi-system, and multi-technology voice call processing service and is depicted in more detail in FIG. 2. In accordance with an exemplary embodiment, Multi-Tenant Call Processing Services 121 is a cloud-based solution that supports multi-tenant voice call processing services and controls at least one access permission database and at least one mobility database, such as Multi-Tenant Mobility Database 132. Multi-Tenant Call Processing Services 121 preferably controls and maintains Multi-Tenant Call State Database 122, for example by writing and reading call information from and to Multi-Tenant Call State Database 122.

Multi-Tenant Call State Database 122 stores the current active call state for every call being processed by Call Processing System 101. the state of the call for active calls, the current audio source of the call, and the priority of the current audio source of the call. The state of the call can be, for example, active voice, hangtime, or call teardown. The current audio source of the call can be, for example, a radio or a console.

Multi-Tenant Mobility Services 131 supports the services necessary to enable radio or console access to the system. In an exemplary embodiment, Multi-Tenant Mobility Services 131 includes the functions of authentication, radio registration, radio affiliation, radio deregistration, console in service, console affiliation, console association, and console out of service. Since the mobility services update and maintain the mobility data associated with these services, access to information in Multi-Tenant Mobility Database 132 preferably flows through Multi-Tenant Mobility Services 131. Therefore, user services, such as group call, preferably access the mobility information via mobility services microservices.

Multi-Tenant Mobility Database 132 preferably stores mobility information for mobile stations and console terminals. In accordance with an exemplary embodiment, Multi-Tenant Mobility Database 132 stores the mobile station (MS) registration state, the MS talkgroup affiliation, the MS site location, the console registration state, and console affiliated talkgroup information. Multi-Tenant Mobility Database 132 can be, for example, an integrated Home Location Register (iHLR), a Gateway HLR (GHLR), a Visitor Location Register (VLR), or a combination of one or more of the above.

In the exemplary embodiment depicted in FIG. 1, LMR System RAN 112 is an ASTRO digital two-way radio communications network that is designed specifically for law enforcement, fire and medical services to communicate with each other during emergency situations. LMR System RAN 112 is a mission critical voice and data communication network and can operate in the 700 MHz, 800 MHz, 900 MHz, UHF and VHF bands for voice and data operation.

In an exemplary embodiment, each of the RANs 112-115 include multiple sites, each site equipped with a plurality of base stations. Each RAN 112-115 also preferably includes software and hardware to allow for fallback operation, which occurs when a RAN desires to operate apart from Call Processing System 101.

In the exemplary embodiment depicted in FIG. 1, LMR System RAN 113 is also an ASTRO digital two-way radio communications network. In this exemplary embodiment, LMR System RAN 113 has a different Wide Area Communications Network (WACN)/System ID information than LMR System RAN 112.

In the exemplary embodiment depicted in FIG. 1, LMR System RAN 114 is a MotoTRBO LMR system that preferably operates in multi-system, cloud-based mode. When the connection between LMR System RAN 114 and Multi-Tenant Call Processing Services 121 goes down, LMR System RAN 114 can fall back to single site operation. This same functionality of falling back to single site operation preferably exists for all RANs in FIG. 1, for example (LMR System RAN 112, LMR System RAN 113, and LTE System RAN 115.

In an exemplary embodiment depicted in FIG. 1, LTE System RAN 115 is an LTE RAN that provides broadband access and services to subscribers.

FIG. 2 depicts multi-tenant call processing services function 121 in additional detail in accordance with an exemplary embodiment of the present invention.

Multi-Tenant Call Processing Services 121 comprises Multi-Tenant Voice/Data Services Processor 201, Audio Services Processor 202, Resource Management Processor 203, and Access Control Processor 204.

Multi-Tenant Voice/Data Services Processor 201 performs the processing of voice calls and data services for mobile devices utilizing Multi-Tenant Call Processing Services 121. In accordance with an exemplary embodiment, the mobile devices utilizing Multi-Tenant Voice/Data Services Processor 201 can be of any technology that is connected to Multi-Tenant Voice/Data Services Processor 201 via the RAN Adaptation layer, which includes RAN Adapters 102-105. Multi-Tenant Voice/Data Services Processor 201 stores and retrieves data in Multi-Tenant Call State Database 122.

Audio Services Processor 202 performs audio functions necessary to support Multi-Tenant Voice/Data Services Processor 201. Audio Services Processor 202, for example, performs the functions of vocoding, devocoding, transcoding, encryption, and decryption. Audio Services Processor 202 may also perform audio routing services, for example, duplication of audio packets and routing to target RAN endpoints, such as RF Sites.

Resource Management Processor 203 provides integrated resource management for multiple systems and multiple technologies. In an exemplary embodiment, Resource Management Processor 203 provides overall call resource management based on a call state determined by each technology. In addition, Resource Management Processor 203 preferably determines the overall call state, such as grant, busy, or reject.

In the exemplary embodiment depicted herein, Resource Management Processor 203 interacts with the resource management processors within the RANs connected to call processing system 101. For example, Resource Management Processor 203 obtains channel/slot resources for each Astro RAN, such as RAN 112 and RAN 113 in FIG. 1. Each RAN preferably includes multiple sites and consoles, and preferably uses ASTRO resource allocation rules. Resource Management Processor 203 preferably obtains slot resources for MOTOTRBO RAN 114 that includes a talkgroup member, preferably using MOTOTRBO resource allocation rules. Similarly, Resource Management Processor 203 preferably uses an Rx interface to obtain bearers per radio for critical users when interfacing with LTE RAN 115, preferably using LTE resource management rules. In accordance with an exemplary embodiment, Resource Management Processor 203 obtains resources from an associated RA.

Access Control Processor 204 isolates data needed for a service to only those needing access. By protecting shared data, privacy is enhanced. Access Control Processor 204 preferably controls access of a calling party and a called party based upon whether the calling party and the called party are allowed to perform a service requested and also whether the calling party and the called party are allowed to perform the requested service at the sites where the service was requested. Access Control Processor 204 also controls access for group calls, such as talkgroup calls, preferably by accessing subscriber access control (SAC) database and retrieving SAC records for each mobile device participating in the call. For talkgroup calls, this includes verifying access to the requested service and whether the requested service is allowed at the site.

FIG. 3 depicts a schematic diagram of LMR System RAN Adapter 102 in accordance with an exemplary embodiment of the present invention. In the exemplary embodiment depicted in FIG. 3, LMR System RAN Adapter 102 includes an input port 301, a processor 303, a database 305, and an output port 307. Input port 301 and processor 303 communicate over one or more communication lines or buses, as do processor 303 and output port 307. Wireless connections or a combination of wired and wireless connections are also possible.

Input port 301 receives electronic signals and messages from LMR System RAN 112, Multi-Tenant Call Processing Services 121, and Multi-Tenant Mobility Services 131. Output port 307 transmits signals and messages to LMR System RAN 112, Multi-Tenant Call Processing Services 121, and Multi-Tenant Mobility Services 131. As described above, each of these RAN Adapters transmits and receives signals and messages from associated RANs. Input port 301 and output port 307 are electrically connected to processor 303. Although depicted in FIG. 3 as two separate elements, input port 301 and output port 307 can be a single element.

Processor 303 may include a microprocessor, application-specific integrated circuit (ASIC), field-programmable gate array, or another suitable electronic device. Processor 303 obtains and provides information (for example, from database 305 and/or input port 301), and processes the information by executing one or more software instructions or modules, capable of being stored, for example, in a random access memory (“RAM”) area of database 305 or a read only memory (“ROM”) of database 305 or another non-transitory computer readable medium, such as Multi-Tenant Call State Database 122. The software can include firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. Processor 303 is configured to retrieve from database 305 and execute, among other things, software related to the control processes and methods described herein.

Database 305 can include one or more non-transitory computer-readable media, and may include a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, as described herein. In the embodiment illustrated, database 305 stores, among other things, instructions for processor 303 to carry out the method of FIG. 4.

FIG. 4 depicts a call flow diagram 400 of a method for initiating a call between first mobile device 122 located at a first communication system and second mobile device 124 located at a second communication system in accordance with an exemplary embodiment of the present invention. In accordance with the exemplary embodiment depicted in FIG. 4, First Communication System 112 and Second Communication System 114 are different communication systems, although this process is effective when a mobile device initiates a group call to another mobile device on the same communication system. It should also be understood that this invention works for two communication systems that are utilizing the same over the air (OTA) protocol, such as LMR ASTRO, LMR MotoTRBO, or LTE, or whether the two OTA protocols are different. This is facilitated at least in part because the call processing functionality is being performed at Cloud-Based Call Processing Services 121, which is capable of processing calls for multiple technologies, from multiple systems, and for multiple tenants.

First Mobile Device 122 sends Call Request message 401 to LMR System 1 RAN 112. Call Request message 401 is preferably received at a base station within LMR System 1 RAN 112.

RAN 112 sends Call Request message 402 to LMR System RA 102. Call Initiation Request message 401 comprises a request to complete a call with Second Mobile Device 124.

LMR System RA 102 determines (403) RAN-specific access parameters for First Mobile Device 122 and Second Mobile Device 124. In the exemplary embodiment where the call is a talkgroup call, parameters relating to the talkgroup are also determined.

LMR System RAN Adapters 102 sends Call Initiation Request message 405 to Cloud-Based Group Call Service 121. CP Call Initiation Request message 405 preferably includes the RAN-specific access parameters and call initiation information for First Mobile Device 122 and Second Mobile Device 124. In the exemplary embodiment where the call is a talkgroup call, talkgroup parameters are included in Call Initiation Request message 405.

Cloud-Based Group Call Service 121 sends Obtain Mobility Info message 406 to Cloud-Based Mobility Service 131. Obtain Mobility Info message 406 preferably includes information pertaining to Mobile Device 124, such as capabilities, location, and other required parameters.

Cloud-Based Mobility Service 131 retrieves (407) mobility information for mobile device 122 and mobile device 124. In the exemplary embodiment where the call is a talkgroup call, Cloud-Based Mobility Service 131 retrieves mobility information related to Mobile Device 122, Mobile Device 124, and the talkgroup.

Cloud-Based Mobility Service 131 sends Mobility Information message 408 to Cloud-Based Group Call Service 121. Mobility Information message 408 preferably includes the information that was obtained in step 407.

Cloud-Based Group Call Service 121 sends Obtain Resources message 409 to LMR System RA 102. Obtain Resources message 409 preferably includes a list of the resources at LMR System 1 RAN 112 that are necessary to complete the call.

Cloud-Based Group Call Service 121 sends Obtain Resources message 410 to LMR System RA 104. Obtain Resources message 410 preferably includes a list of the resources at LMR System 3 RAN 114 that are necessary to complete the call. It should be understood that Cloud-Based Group Call Service 121 can send message 409 prior to message 410, as is depicted in FIG. 4, or can send message 410 prior to message 409, or can send the messages simultaneously.

LMR System RA 102 determines (411) the resources necessary for the call. These resources can include, for example, base stations and channels.

LMR System RA 104 determines (412) the resources necessary for the call. These resources can include, for example, base stations and channels.

Upon determining the resources necessary for the call, LMR System RA 104 sends Resources Allocated message 414 to Cloud-Based Group Call Service 121. Resources Allocated message 414 preferably includes an indication of the success of the resource allocation, and may also include information relating to the resources that were allocated for this call.

Upon determining the resources necessary for the call, LMR System RA 102 sends Resources Allocated message 413 to Cloud-Based Group Call Service 121. Resources Allocated message 413 preferably includes the success of the resource allocation, and may also include information relating to the resources that were allocated for this call. It should be understood that the order in which messages 413 and 414 are sent and received is not significant to the operation of this invention.

Cloud-Based Group Call Service 121 completes (415) the call setup for that call between first mobile device 122 and second mobile device 124.

Cloud-Based Group Call Service 121 sends Start Call message 416 to LMR System RA 102.

Cloud-Based Group Call Service 121 sends Start Call message 417 to LMR System RA 104. As mentioned above, the order of the sending and receiving Start Call message 416 and Start Call message 417 is not relevant to the operation of the current invention.

LMR System RA 102 sends Call Grant message 418 to RAN 112. RAN 112 sends Call Grant message 419 to Mobile Device 122.

LMR System RA 104 sends Call Grant message 420 to RAN 113. RAN 113 sends Call Grant message 421 to Mobile Device 124.

Call 422 commences between First Mobile Device 122 and Second Mobile Device 124.

In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.

Moreover in this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has”, “having,” “includes”, “including,” “contains”, “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a”, “has . . . a”, “includes . . . a”, “contains . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially”, “essentially”, “approximately”, “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.

It will be appreciated that some embodiments may be comprised of one or more generic or specialized electronic processors (or “processing devices”) such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (FPGAs) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and/or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.

Moreover, an embodiment can be implemented as a computer-readable storage medium having computer readable code stored thereon for programming a computer (e.g., comprising an electronic processor) to perform a method as described and claimed herein. Examples of such computer-readable storage mediums include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a PROM (Programmable Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory) and a Flash memory. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.

The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter. 

We claim:
 1. A method for initiating a talkgroup call between a first mobile device located at a first communication system and a second mobile device located at a second communication system, the method comprising: receiving a talkgroup call request from the first mobile device at a first Radio Access Network (RAN) Adaptor (RA), the talkgroup call request comprising a request to complete a talkgroup call with the second mobile device; determining first RAN-specific access parameters for the first mobile device at the first RA; sending a talkgroup call initiation request from the first RA to a cloud-based group call service, the talkgroup call initiation request including the first RAN-specific access parameters and talkgroup call initiation information; determining second RAN-specific access parameters for the second mobile device at a second RA associated with the second mobile device; establishing first resources specific to the first RAN in the first RA; establishing second resources specific to the second RAN in the second RA; and completing, by the cloud-based group call service, the talkgroup call between the first mobile device and the second mobile device using the first resources and the second resources.
 2. The method of claim 1, wherein the first communication system and the second communication system are different.
 3. The method of claim 1, wherein the first communication system and the second communication system are the same.
 4. The method of claim 1, wherein the step of determining second RAN-specific access parameters for the second mobile device at the second RA comprises determining talkgroup-specific parameters for the talkgroup call.
 5. The method of claim 1, further comprising performing call processing functionality at the cloud-based group call service.
 6. A method for initiating a call between a first mobile device located at a first communication system and a second mobile device located at a second communication system, the method comprising: receiving a call request from the first mobile device at a first Radio Access Network (RAN) Adaptor (RA), the call request comprising a request to complete a call with the second mobile device; determining first RAN-specific access parameters for the first mobile device at the first RA; sending a call initiation request from the first RA to a cloud-based group call service, the call initiation request including the first RAN-specific access parameters and call initiation information; determining second RAN-specific access parameters for the second mobile device at a second RA associated with the second mobile device; establishing first resources specific to the first RAN in the first RA; establishing second resources specific to the second RAN in the second RA; and completing, by the cloud-based group call service, the call between the first mobile device and the second mobile device using the first resources and the second resources.
 7. The method of claim 6, wherein the first communication system and the second communication system are different.
 8. The method of claim 6, further comprising obtaining, by the cloud-based group call service, mobility information from a cloud-based mobility service.
 9. The method of claim 6, further comprising performing call processing functionality at the cloud-based group call service.
 10. A Radio Access Network (RAN) Adapter (RA) for completing a call between a first mobile device located at a first communication system and a second mobile device located at a second communication system, the RA comprising: an input port for receiving a talkgroup call request from the first mobile device at a first Radio Access Network (RAN) Adaptor (RA), the talkgroup call request comprising a request to complete a talkgroup call with the second mobile device; a processor that performs determining first RAN-specific access parameters for the first mobile device at the first RA; an output port for sending a talkgroup call initiation request from the first RA to a cloud-based group call service, the talkgroup call initiation request including the first RAN-specific access parameters and talkgroup call initiation information; wherein the processor further performs establishing first resources specific to the first RAN in the first RA; and wherein the input port further receives a start call message from a cloud-based group call service.
 11. The RA of claim 10, wherein the input port further receives mobility information from a cloud-based mobility service.
 12. The RA of claim 11, wherein the mobility information comprises talkgroup information.
 13. The RA of claim 12, wherein the talkgroup information comprises information relating to talkgroup mobile devices that are members of the talkgroup.
 14. The RA of claim 12, wherein the talkgroup information comprises information relating to talkgroup sites that currently have a member of the talkgroup registered. 